1. Field of the Invention
This application relates generally to apparatus for planting onion seeds, and the like, and more particularly to improvements in the construction and mounting of disc-carrying arms employed with onion planters and similar devices.
2. Description of the Prior Art
My co-pending U.S. application for patent, Ser. No. 534,668, a continuation of abandoned U.S. application Ser. No. 305,946 and now U.S. Pat. No. 4,478,159, is directed to apparatus for planting seeds, and the like, wherein a plurality of planter-disc carrying arms are pivotally mounted on a frame of the apparatus so as to permit the discs to pass over debris and other obstructions lying in the path of the planter apparatus. The construction of these arms includes a generally longitudinally extending portion pivotally mounted on an associated subframe and terminating in a generally perpendicular leg spaced from the associated subframe and on which is journaled a set of planter discs. A problem has been encountered with this construction, however, inasmuch as side forces exerted on the generally longitudinally extending portion of the arm require that portion to be strongly braced against buckling. Solutions to this problem have ranged from the provision of an elongated piece of bracing material welded or otherwise attached to a side of the longitudinally extending portion of each arm, to the construction of the longitudinally extending portion of each of the arms as a hollow tube having a rectangular cross-section. In general, however, these solutions increase the weight of the arm, and thus the force required to lift the arm over obstacles encountered as the planter traverses a field, and accordingly none has been entirely satisfactory.
Another problem encountered with the use of planter apparatus constructed in accordance with that disclosed in my prior, co-pending, U.S. application for patent, Ser. No. 534,668, now U.S. Pat. No. 4,478,156 is that on occasion a spring-biased rod normally extending vertically above each of the disc-carrying arms of the planter becomes disengaged, permitting the associated planter arm to drop down more than a predetermined distance relative to the soil being worked, with resulting damage to the seed dispensing hoses, and the like, of the planter assembly. In addition, although the aforementioned spring-biased rod provides a satisfactory control for the planter arms when a heavy soil is being worked, it has been found that the adjustment provided by such a spring arrangement is often unsatisfactory when a light soil is being planted.